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SRRL AOD Instrument Descriptions and Histories


Model Measurement
Notes (below)		 Units Install
Date		 Removal
Date		 Current
SN		 Current
CF
(calc) Aerosol Optical Depth (AOD) unitless 06/11/2013 - - -
Aerosol Optical Depth at 400, 500, 675, 870, and 1020nm. These are calculated directly on the sun.
(calc) Almucantar Aerosol Optical Depth (AOD-DIF) unitless 06/11/2013 12/19/2021 - -
Almucantar Aerosol Optical Depth at 400, 500, 675, 870, and 1020nm. These are calculated at several scattering angles away from the sun.
(calc) Single Scattering Albedo (SSA) unitless 06/11/2013 - - -
Single Scattering Albedo at 400, 500, 675, 870, and 1020nm.
(calc) Asymmetry unitless 06/11/2013 - - -
Asymmetry Factor at 400, 500, 675, 870, and 1020nm.
(calc) m unitless 06/11/2013 - - -
Real part of refractive index at each wavelength.
(calc) k unitless 06/11/2013 - - -
Imaginary part of refractive index at each wavelength.
(calc) α (alpha) unitless 06/11/2013 - - -
Angstrom exponent
(calc) β (beta) unitless 06/11/2013 - - -
Angstrom turbidity coefficient, i.e. calculated aerosol optical depth at 1000nm.
(calc) IDCR and IDCI unitless 07/01/2015 12/19/2021 - -
Zero means that the inversion procedure was not able to retrieve the real or imaginary part and fixed values have been assumed. One means that the inversion was able to retrieved these values.
(calc) Correction unitless 06/11/2013 12/19/2021 - -
Unknown correction value
(calc) AOD Flag unitless 06/11/2013 12/19/2021 - -
Flag that indicates 0 for AOD and 1 for AOD-DIF
(calc) Retrieval error unitless 06/11/2013 12/19/2021 - -
The retrieval error as a fraction. Multiply by 100 to change to percent.
(calc) Cloud Flag unitless 04/30/2013 - - -
Flag that indicates 1 for cloudy and 0 for clear.
(calc) Wavelength Count unitless 04/01/2013 - - -
Number of wavelengths found in daily NetCDF file downloaded from SKYNET.
(calc) Radius Count unitless 04/30/2013 - - -
Number of radius values found in daily NetCDF file downloaded from SKYNET.
(calc) Volume Size Distributions nm3/nm2 04/30/2013 - - -
Volume size distributions are obtained at 20 fixed values of radius at:
  • ESR-MRI: 0.0357, 0.0504, 0.0711, 0.1005, 0.1419, 0.2005, 0.2832, 0.4001, 0.5651, 0.7982, 1.128, 1.593, 2.25, 3.178, 4.489, 6.34, 8.956, 12.65, 17.87, 25.24 µm
  • SR-CEReS: 0.012, 0.018, 0.026, 0.038, 0.055, 0.081, 0.118, 0.173, 0.253, 0.37, 0.541, 0.791, 1.156, 1.691, 2.473, 3.617, 5.289, 7.734, 11.31, 16.54 µm
Notes:
  • Raw direct normal data is sampled by Prede POM-01 every 1 minute and a raw zenith/azimuth scan is sampled every 10 minutes. Raw data is sent to ESR/SKYNET every hour for data processing.
  • The SKYNET data processor has three methods (each with two levels, L2A and L2) for proccessing data, the ESR-SunRad, ESR-MRI, and SR-CEReS Methods. Note that SR-CEReS only has one level, L2. The older ESR data processor had two methods (each with two levels, L0 and L1.1) for proccessing data, the ESR-SunRad and SkyRad Methods.
  • All data streams (methods & levels) are grabbed by MIDC once a day (4 hours after midnight) from the SKYNET web site and converted to "classic" Campbell data logger format so that it can be made available on the MIDC web site. Resulting sample rate will be as every 10 minutes (every 1 minute for ESR-SunRad).
  • Data processing at SKYNET can take a couple days for Level L2A (L0 for the older ESR data sets) and a couple months for Level L2 (L1.1 for the older ESR data sets). The SR-CEReS data set goes directly to L2 on a daily basis. SKYNET/ESR does not process data from the 315 and 940nm wavelengths.
  • For the latest data sets, please visit the SKYNET website for an introduction, methodology, and further information regarding the data processsing.
  • For the older data sets, please visit the ESR website for an introduction, methodology, and further information regarding the data processsing.

[NREL] [MIDC] [SRRL AOD]